public class t812 {
    //最大的三角形面积
    public static double largestTriangleArea(int points[][]) {
        double x1, y1, x2, y2, x3, y3, a, b, c, d,s = 0;
        for (int i = 0; i < points.length; i++) {
            for (int j = i + 1; j < points.length; j++) {
                for (int k = j + 1; k < points.length; k++) {
                    x1 = points[i][0];
                    y1 = points[i][1];
                    x2 = points[j][0];
                    y2 = points[j][1];
                    x3 = points[k][0];
                    y3 = points[k][1];
                    a = x2 - x1;
                    b = y2 - y1;
                    c = x3 - x2;
                    d = y3 - y2;
                    s = Math.max(s,Math.abs(a*d-b*c)/2);
                }
            }
        }
        return s;

    }
}
